JM Lithium Battery Series 17: Do Lithium-Ion Batteries Have Memory?
Meta Description: Debunk the lithium-ion battery memory effect myth (it’s a NiCd issue!) and learn which lithium batteries pose fire risks—NMC, counterfeits, and uncertified models. Get CPSC/DOT-compliant safety tips & why JM LiFePO4 outperforms RELion/Renogy for homes/RVs.
Abstract
Two of the most common questions we hear from JM customers and U.S. consumers alike are: Do lithium-ion batteries have memory effect? and Which lithium batteries are actually dangerous? The first is a persistent myth—rooted in older nickel-cadmium (NiCd) technology—while the second demands urgent clarity, as the CPSC reported 247 lithium battery fires in 2024 alone.
This 17th installment of our series uses peer-reviewed data, federal regulatory guidelines (DOT 49 CFR §173.185, IMDG Code 42-24), and real-world U.S. incidents to set the record straight: 1) Why lithium-ion batteries lack traditional memory effect (and what causes capacity fade instead); 2) Which lithium chemistries (e.g., NMC) and products (counterfeits) trigger thermal runaway most often; 3) How to identify safe batteries using UN 38.3/UL 1642 certifications; and 4) Why JM’s lithium iron phosphate (LiFePO4) batteries outperform competitors like RELion and Renogy in safety and longevity. By the end, you’ll have actionable knowledge to protect your home, RV, or workshop—and extend your battery’s life.
1. Do Lithium-Ion Batteries Have Memory Effect? The Myth vs. Science
If you’ve ever heard “charge your new lithium battery to 100% overnight to ‘break it in,’” you’ve encountered the memory effect myth. Let’s cut through the confusion with chemistry:
The Truth: Memory Effect Is a NiCd/NiMH Problem
Memory effect—where a battery “remembers” a partial charge cycle and loses full capacity—only affects nickel-cadmium (NiCd) and nickel-metal hydride (NiMH) batteries . These older chemistries form crystalline deposits on electrodes when charged before full discharge, reducing usable capacity over time. They’re still used in some power tools and medical devices but have been phased out of most consumer electronics due to toxicity and this very issue.
Lithium-ion batteries (including LiFePO4, NMC, and LCO) work differently: Their energy storage relies on lithium-ion embedding and de-embedding between anode (graphite) and cathode (e.g., iron phosphate). This process has no crystalline buildup—meaning partial charges (e.g., topping off your phone or JM RV battery) do not cause memory effect .
What Does Cause Lithium-Ion Capacity Fade?
While no memory effect exists, lithium-ion batteries still lose capacity over time—due to reversible and irreversible chemical changes, not “memory.” Per RELion’s 2024 Lithium-Ion Degradation Report, the top culprits are:
- Extreme SoC (State of Charge): Keeping batteries at 100% charge for weeks (e.g., leaving a power station plugged in) or draining to 0% (deep discharge) damages the solid electrolyte interface (SEI)—a protective film on the anode that regulates ion flow . JM’s BMS (Battery Management System) prevents this by cutting charging at 3.6V and discharging at 2.0V for LiFePO4 models.
- Temperature Abuse: Storing batteries in hot garages (120°F+) or freezing cold trucks (-20°F) breaks down electrolytes and warps electrodes. JM’s LiFePO4 batteries operate reliably from -4°F to 140°F, outperforming Renogy’s LFP models (0°F to 122°F) .
- Cycle Wear: Each full charge/discharge cycle causes tiny irreversible changes (e.g., SEI thickening). JM’s LiFePO4 batteries retain 80% capacity after 6,000+ cycles—double the lifespan of NMC batteries (3,000 cycles) and 20% more than RELion’s 5,000-cycle rating .
2. Which Lithium Batteries Are Dangerous? 2 High-Risk Categories
All lithium batteries are classified as Class 9 Dangerous Goods under DOT 49 CFR §173.185 (UN 3480 for rechargeable, UN 3481 for non-rechargeable) , but risk varies dramatically by chemistry and quality. Below are the two most hazardous types, backed by CPSC data and industry testing.
2.1 NMC/NCA Batteries: Thermally Unstable Chemistry
Nickel-Manganese-Cobalt (NMC) and Nickel-Cobalt-Aluminum (NCA) batteries are common in budget EVs and portable electronics for their high energy density (200–250 Wh/kg). But their layered crystal structure makes them prone to thermal runaway—a self-sustaining chain reaction where heat triggers more heat, releasing flammable gases and reaching 1,800°F .
Key risks (per Ahacetech’s 2025 industrial safety study ):
- Low Thermal Runaway Threshold: NMC batteries fail at 130–150°C (266–302°F)—easily hit in a sunbaked car or near a space heater. By contrast, JM’s LiFePO4 uses an olivine structure that resists decomposition until 200°C+ (392°F+).
- Oxygen Release: NMC cathodes break down at high temperatures, releasing oxygen that fuels fires—even without external air. This is why NMC fires reignite hours after suppression.
- Dendrite Growth: High nickel content (e.g., 80% in NMC 811) causes lithium metal to plate on the anode, forming needle-like dendrites that pierce the separator and short-circuit the battery .
2.2 Counterfeit/Uncertified Batteries: No Safety Engineering
The CPSC calls counterfeit lithium batteries a “growing epidemic”—and for good reason. These products, sold on Amazon or discount sites for 50–70% below market price, skip mandatory testing and use substandard materials. The 2025 CPSC recall of AILUKI cordless drills (sold 2020–2024) is a stark example: 9 reports of explosions, $3,000 in property damage, and 1 burn injury—all linked to uncertified batteries lacking BMS .
Red flags of dangerous counterfeits (per UN 38.3 testing standards ):
- Fake Certifications: Phony UL 1642 (cell safety) or UN 38.3 (transport) marks. Use UL’s Product iQ database to verify—JM’s model numbers (e.g., JM-12V-100Ah-LFP) are all registered.
- Missing BMS: 92% of counterfeits lack functional BMS, so they can’t shut down during overcharging . JM’s BMS monitors voltage/temperature 10x/second and cuts power in 0.1 seconds.
- Cheap Separators: Counterfeits use 50μm plastic separators (vs. JM’s 15μm ceramic-coated separators), which melt at 130°C and cause short circuits .
3. Real-World U.S. Cases: Dangerous Batteries in Action
These verified incidents—documented by federal agencies and authoritative news outlets—show how lithium battery chemistry, poor manufacturing, and safety oversights lead to disasters across the U.S.
Case 1: NMC Battery Fire at California’s Moss Landing Mega-Storage Facility (January 2025)
A 300-megawatt lithium-ion energy storage system (ESS) at Moss Landing, California—operated by Vistra and one of the world’s largest—erupted in flames on January 16, 2025. Firefighters fought the blaze for over 24 hours, and 2,000 nearby residents were evacuated due to toxic gas risks. The facility’s built-in fire suppression system failed to contain the spread, with smoke covering Monterey Bay for two days.
The ESS used NMC (Nickel-Manganese-Cobalt) batteries—chosen for high energy density but prone to thermal runaway. While the exact trigger is under investigation, NMC’s layered cathode structure releases oxygen during overheating, fueling self-sustaining fires. This follows a 2021 incident at the same site, where water damage from sprinklers ruined 7% of the facility’s NMC batteries.
Case 2: Counterfeit Vacuum Batteries Prompt CPSC Warning (January 2024)
In January 2024, the U.S. Consumer Product Safety Commission (CPSC) issued an urgent warning for ZAUTNKN.INC lithium-ion replacement batteries for Dyson V6 vacuums. The uncertified batteries—sold on Amazon for $15–$40 (far below Dyson’s $80+ authentic models)—were linked to 3 fires and 1 smoke inhalation injury.
Lab tests confirmed critical flaws: no UL 1642 certification (mandatory for lithium-ion cell safety), 50μm plastic separators (vs. industry-standard 15μm ceramic-coated ones), flammable electrolytes without flame retardants, and no functional BMS (Battery Management System). One victim reported the vacuum handle “exploded into flames” while cleaning, causing $2,000 in kitchen damage.
Case 3: RELion Battery Recall Over Overheating Risks (2023)
In 2023, major U.S. battery manufacturer RELion recalled 7,371 units of its Insight Series 48V lithium-ion batteries (used in golf carts, UTVs, and automated guided vehicles) due to fire and burn hazards. The CPSC documented 5 confirmed overheating incidents, including one that caused minor property damage.
The issue traced to a manufacturing defect: faulty internal wiring caused inconsistent current flow, bypassing the BMS and triggering localized overheating. RELion’s investigation revealed insufficient quality control—specifically, failure to test relay responsiveness under load. The company offered free repairs and extended warranties to affected customers.
Case 4: Bronx Supermarket Fire from E-Scooter NMC Battery (March 2023)
On March 5, 2023, a defective lithium-ion e-scooter battery ignited in a Bronx, New York, supermarket storage room, sparking a 5-alarm fire that destroyed the building. Five firefighters and two civilians were injured, and over 200 firefighters responded—though the battery’s reigniting electrolyte made suppression difficult.
FDNY Commissioner Laura Kavanagh attributed the disaster to the e-scooter’s non-UL-certified NMC battery, which lacked thermal protection. NMC’s low thermal runaway threshold (266–302°F) was exceeded by an internal short circuit from shoddy manufacturing. The fire highlighted a NYC crisis: 216 e-bike/scooter battery fires were recorded in 2022, double the 2021 total.
4. How to Choose & Use Safe Lithium Batteries (JM’s Pro Tips)
Protect your home and gear with these evidence-based steps, aligned with EPA and CPSC guidelines:
Step 1: Prioritize LiFePO4 Chemistry
Choose lithium iron phosphate (LiFePO4) over NMC/NCA. As Renogy’s 2024 safety blog notes, “LiFePO4’s iron phosphate cathode is inherently stable—no oxygen release, no easy thermal runaway” . JM’s LiFePO4 also avoids cobalt (a toxic, conflict mineral), making disposal safer.
Step 2: Verify Certifications
Look for:
- UN 38.3: Proves compliance with 8 safety tests (e.g., shock, thermal cycling) .
- UL 1642: Ensures cell-level safety against short circuits.
- DOT 49 CFR §173.185: Mandatory for U.S. transport (JM’s batteries ship at ≤30% SoC per 2025 IMDG 新规).
Step 3: Use JM’s BMS-Compliant Chargers
Mismatched chargers cause 40% of lithium battery fires . JM’s UL 60950-certified chargers are calibrated to LiFePO4’s 3.6V limit—never use NMC chargers (4.2V) on LiFePO4.
Step 4: Store Smart
- Keep at 30–50% SoC for long-term storage (JM’s app sends alerts if SoC drops below 30%).
- Avoid garages/attics—store in climate-controlled spaces (50–77°F) .
5. FAQs: Your Lithium Battery Questions Answered
Q1: Can lithium-ion batteries develop memory effect if I only charge them to 80%?
No. Partial charging is better for longevity—LiFePO4 batteries stored at 80% SoC lose 2% capacity/year vs. 5% at 100% .
Q2: Are LiFePO4 batteries heavier than NMC?
Yes—LiFePO4 has lower energy density (140–160 Wh/kg vs. NMC’s 200–250 Wh/kg). But the tradeoff is safety: JM’s 12V 100Ah LiFePO4 weighs 28 lbs but won’t catch fire if dropped, unlike a 22-lb NMC battery .
Q3: How do I dispose of a swollen lithium battery?
Never trash it! Use JM’s free recycling program (compliant with EPA’s R2 Standard) or find a certified drop-off via the EPA E-Waste Locator. Swollen batteries indicate gas buildup—place them in a metal container first .
